In the field of vehicle cameras, an imaging apparatus has been disclosed, in which polarizers are provided in an optical path of a compound eye camera with a different polarization axis for each ommatidium, for detecting a road surface condition or a lane (Patent Document No. 1).
With cameras in the medical/beauty field, such as endoscopic systems and skin diagnosis systems, imaging apparatuses have been commercialized, which obtain both a non-polarized light image and a polarized light image.
These imaging apparatuses include a polarized illumination for irradiating a biological tissue with non-polarized light and light oscillating in the direction of a predetermined polarization axis. When a biological tissue is irradiated with light of a predetermined polarized component, reflected light off the biological surface is specular reflection light of which the polarized component is maintained, whereas reflected light off a living body deep part is scattered reflection light of which the polarized component is disturbed. Therefore, it is possible to obtain an image of the biological surface and an image of the living body deep part by arranging, on the side of the imaging apparatus, a polarization filter that passes therethrough light oscillating in a direction parallel to the polarization axis of the polarized illumination and a polarization filter that passes therethrough light oscillating in a direction perpendicular to the polarization axis of the illumination.
Such imaging apparatuses for obtaining images of different polarization characteristics have been disclosed in the art (Patent Document Nos. 2 and 3).